From eb3f705c39e022bf3d07c27d6e5b8ddfed638992 Mon Sep 17 00:00:00 2001
From: Linus Nordberg <linus@nordu.net>
Date: Mon, 27 Feb 2017 14:48:08 +0100
Subject: Look for root last in list, not anywhere in list.
Even if verify_chain() should not return a root cert that is not last
in the chain, the code is now less confusing to read.
Also, rename normalise_chain/3 to verify_chain to reflect what it
actually does.
---
src/x509.erl | 72 ++++++++++++++++++++++++++++++------------------------------
1 file changed, 36 insertions(+), 36 deletions(-)
(limited to 'src')
diff --git a/src/x509.erl b/src/x509.erl
index 0b32c4e..f44e36f 100644
--- a/src/x509.erl
+++ b/src/x509.erl
@@ -21,14 +21,14 @@
-spec normalise_chain([binary()], [binary()]) -> {ok, [binary()]} |
{error, reason()}.
normalise_chain(AcceptableRootCerts, CertChain) ->
- case normalise_chain(AcceptableRootCerts, CertChain, ?MAX_CHAIN_LENGTH) of
+ case verify_chain(AcceptableRootCerts, CertChain, ?MAX_CHAIN_LENGTH) of
{false, Reason} ->
{error, Reason};
{true, Root} ->
- case lists:member(Root, CertChain) of
- true ->
+ case lists:last(CertChain) of
+ Root ->
{ok, CertChain};
- false ->
+ _ ->
{ok, CertChain ++ [Root]}
end
end.
@@ -68,8 +68,8 @@ detox(LeafDer, ChainDer) ->
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Private functions.
--spec normalise_chain([binary()], [binary()], integer()) ->
- {false, reason()} | {true, [binary()]}.
+-spec verify_chain([binary()], [binary()], integer()) ->
+ {false, reason()} | {true, [binary()]}.
%% @doc Verify that the leaf cert or precert has a valid chain back to
%% an acceptable root cert. The order of certificates in the second
%% argument is: leaf cert in head, chain in tail. Order of certs in first
@@ -77,10 +77,10 @@ detox(LeafDer, ChainDer) ->
%%
%% Return {false, Reason} or {true, Root} where Root is a CA cert from
%% AcceptableRootCerts signing the root of the chain.
-normalise_chain(_, _, MaxChainLength) when MaxChainLength =< 0 ->
+verify_chain(_, _, MaxChainLength) when MaxChainLength =< 0 ->
%% Chain too long.
{false, chain_too_long};
-normalise_chain(AcceptableRootCerts, [TopCert], MaxChainLength) ->
+verify_chain(AcceptableRootCerts, [TopCert], MaxChainLength) ->
%% Check root of chain.
case lists:member(TopCert, AcceptableRootCerts) of
true ->
@@ -96,9 +96,9 @@ normalise_chain(AcceptableRootCerts, [TopCert], MaxChainLength) ->
Root -> {true, Root}
end
end;
-normalise_chain(AcceptableRootCerts, [Cert|Rest], MaxChainLength) ->
+verify_chain(AcceptableRootCerts, [Cert|Rest], MaxChainLength) ->
case signed_by_p(Cert, hd(Rest)) of
- true -> normalise_chain(AcceptableRootCerts, Rest, MaxChainLength - 1);
+ true -> verify_chain(AcceptableRootCerts, Rest, MaxChainLength - 1);
false -> {false, signature_mismatch}
end.
@@ -414,21 +414,21 @@ valid_cert_test_() ->
%% #'OTPCertificate'{}. The error is
%% {invalid_choice_tag,{22,<<"US">>}}}} in
%% 'OTP-PUB-KEY':Func('OTP-X520countryname', Value0).
- ?_assertMatch({true, _}, normalise_chain(nth(1, Chains),
- nth(1, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(1, Chains),
+ nth(1, Chains), 10)),
%% Self-signed so fail.
?_assertMatch({false, root_unknown},
- normalise_chain(KnownRoots,
- nth(2, Chains), 10)),
+ verify_chain(KnownRoots,
+ nth(2, Chains), 10)),
%% Leaf signed by known CA, pass.
- ?_assertMatch({true, _}, normalise_chain(KnownRoots,
- nth(3, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(KnownRoots,
+ nth(3, Chains), 10)),
%% Proper 3-depth chain with root in KnownRoots, pass.
%% Bug CATLFISH-19 --> [info] rejecting "3ee62cb678014c14d22ebf96f44cc899adea72f1": chain_broken
%% leaf sha1: 3ee62cb678014c14d22ebf96f44cc899adea72f1
%% leaf Subject: C=KR, O=Government of Korea, OU=Group of Server, OU=\xEA\xB5\x90\xEC\x9C\xA1\xEA\xB3\xBC\xED\x95\x99\xEA\xB8\xB0\xEC\x88\xA0\xEB\xB6\x80, CN=www.berea.ac.kr, CN=haksa.bits.ac.kr
- ?_assertMatch({true, _}, normalise_chain(KnownRoots,
- nth(4, Chains), 3)),
+ ?_assertMatch({true, _}, verify_chain(KnownRoots,
+ nth(4, Chains), 3)),
%% Verify against self, pass.
%% Bug CATLFISH-??, can't handle issuer keytype ECPoint.
%% Issuer sha1: 6969562e4080f424a1e7199f14baf3ee58ab6abb
@@ -442,31 +442,31 @@ valid_cert_test_() ->
%% Supposedly problematic chains from Google Aviator, fatal.
%% 00459972: asn1: syntax error: sequence truncated
- ?_assertMatch({true, _}, normalise_chain(nth(7, Chains),
- nth(7, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(7, Chains),
+ nth(7, Chains), 10)),
%% 1402673: x509: RSA modulus is not a positive number
- ?_assertMatch({true, _}, normalise_chain(nth(8, Chains),
- nth(8, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(8, Chains),
+ nth(8, Chains), 10)),
%% 1345105: asn1: syntax error: IA5String contains invalid character
- ?_assertMatch({true, _}, normalise_chain(nth(9, Chains),
- nth(9, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(9, Chains),
+ nth(9, Chains), 10)),
%% 1557693: asn1: structure error: integer too large
- ?_assertMatch({true, _}, normalise_chain(nth(10, Chains),
- nth(10, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(10, Chains),
+ nth(10, Chains), 10)),
%% Supposedly problematic chains from Google Aviator, non-fatal.
%% 16800: x509: negative serial number
%% a.pem
- ?_assertMatch({true, _}, normalise_chain(nth(11, Chains),
- nth(11, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(11, Chains),
+ nth(11, Chains), 10)),
%% 22487: x509: unhandled critical extension ([2 5 29 32])
%% b.pem
- ?_assertMatch({true, _}, normalise_chain(nth(12, Chains),
- nth(12, Chains), 10)),
+ ?_assertMatch({true, _}, verify_chain(nth(12, Chains),
+ nth(12, Chains), 10)),
%% 5198: x509: certificate contained IP address of length 8
%% c.pem
- ?_assertMatch({true, _}, normalise_chain(nth(13, Chains),
- nth(13, Chains), 10))
+ ?_assertMatch({true, _}, verify_chain(nth(13, Chains),
+ nth(13, Chains), 10))
] end}.
chain_test_() ->
@@ -480,19 +480,19 @@ chain_test(C0, C1) ->
%% Root not in chain but in trust store.
?_assertEqual({ok, [C0, C1]}, normalise_chain([C1], [C0])),
%% Same, but chain too long.
- ?_assertEqual({false, chain_too_long}, normalise_chain([C1], [C0], 1)),
+ ?_assertEqual({false, chain_too_long}, verify_chain([C1], [C0], 1)),
%% Root in chain and in trust store.
?_assertEqual({ok, [C0, C1]}, normalise_chain([C1], [C0, C1])),
%% Same, but chain too long.
- ?_assertEqual({false, chain_too_long}, normalise_chain([C1], [C0, C1], 1)),
+ ?_assertEqual({false, chain_too_long}, verify_chain([C1], [C0, C1], 1)),
%% Root not in trust store.
?_assertEqual({error, root_unknown}, normalise_chain([], [C0, C1])),
%% Selfsigned. Actually OK.
?_assertEqual({ok, [C0]}, normalise_chain([C0], [C0])),
%% Same, still OK.
- ?_assertEqual({true, C0}, normalise_chain([C0], [C0], 1)),
+ ?_assertEqual({true, C0}, verify_chain([C0], [C0], 1)),
%% Max chain length 0 is not OK.
- ?_assertEqual({false, chain_too_long}, normalise_chain([C0], [C0], 0))
+ ?_assertEqual({false, chain_too_long}, verify_chain([C0], [C0], 0))
].
%%-spec read_certs(file:filename()) -> [string:string()].
--
cgit v1.1